The load-sensitive hydraulic system is a hydraulic circuit that senses system pressure and flow requirements and provides only the required flow and pressure, so that the load-sensitive control system has a lower power loss and its efficiency is much higher than that of a conventional hydraulic system. Load-sensitive systems are widely used in hydraulic systems of construction machinery, such as truck cranes, excavators, rotary drilling rigs, and concrete pump trucks. Load-sensitive multi-path valve is one of the important components of the load-sensitive system, and its performance directly affects the power loss, micro-motion characteristic, dynamic characteristic and composite action coordination performance of the load-sensitive system.
The influence of the pressure compensation valve in the load-sensitive multi-path valve is not considered in the pressure loss testing method in the JB/T 8729-2013 “Hydraulic multi-path change valve”. The measured pressure loss is the sum of the pressure loss and the pressure difference between the pressure compensators, rather than the true pressure loss, and it is impossible to evaluate the pressure loss characteristic of the load-sensitive multi-path valve. The loading process in the existing pressure loss test is loaded with a manual one-way throttle valve, and the multi-path valve commutation adopts a manual proportional pilot valve control. In this way, the adjustment process is inconvenient, and pressure and flow adjustments of the main pump are manually controlled, and the operation is inconvenient. At the same time, the description of the pressure loss testing method, micro-motion characteristic testing method, and saturation resistant characteristic testing method for multi-path valves in the standard are not detailed, and the accurate acquisition of relevant data cannot be achieved during the actual tests.